<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<body>
<script>

  class Base{
    constructor(props) {
      console.log('父类的构造');
      this.props = props;
    }

    sayBase() {
      return this.props;
    }
  }

  class A extends Base {

  }

  console.log(new A(10).props);

</script>
</body>
</html>
